Wiring 4 subs/Ohms question

[anger 10+ year member]

Hey everybody, I've received good advice here in the past and am back for more...

So, here's my situation:

I'm running 4 12" Fosgate Punch HE's. They were powered by a fosgate bd1000.1 (1000W Mono). The amp quit on me so I replaced it with this "ProAcoustic" 1600W 2 channel amp (see pic). I've never heard of this brand and can't find any info on the amp. I guess my first question would be, Can anyone provide the specs for this thing?

Also, since I've had this new amp installed, the subs put out great bass for about 5 min, then it starts to cut out and then completely quit...and the protect light on the amp illuminates...

I took it to a local shop for some advice and they suggested instead of bridging, to run 2 subs to one channel and the other two subs to the second channel.. They're saying it's an problem with ohms. I'm not yet convinced that this will fix my problem, so wanted to run it by the community here before I start rewiring.

I know the previous amp I used (Fosgate bd1000.1) was stable at 2 ohms, and I believe the way the subs are wired, it should be running at 2 ohms?? All four are wired in sequence (+&- from terminal to first sub, +&- from first sub to second sub, and so on)

Is there a different way I should be wiring the subs together in the box?

I'd be happy to provide anymore information that would help you help me...ANY help is appreciated.

Thanks!

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[PSturmer 10+ year member]

if the amp sees a too small of ohm load it will go into protect. lookup diagrams of series and parallel and see which one resembles your setup.

 

[anger 10+ year member]

So, I rewired the subs to run the amp at 4ohms. What a difference...Sounds so ****** compared to how I had it before with the fosgate bd1000....I've been trying to tune it for a few days now with no luck. There's just no thump and puts out real "muddy" sound.

Guess I should have looked into having the bd1000 repaired rather than being so quick to swap it out. Anyways...lesson learned. Thanks for the help PSturmer.

 

[basswiigee]

what ohm are ur subs lets start there, and that amp was a downgrade imo

 

[anger 10+ year member]

They're 4 ohm subs. I agree that the amp was a downgrade...I'm also finding that, after putting out decent sound for 20 min or so, the bass will cut out completely (amp isn't going into protect and i checked all the connections). Any ideas?

 

[Jepalan]

I found the specs on your amp (at bottom). It claims to be 2-ohm stable, so you should be able to run two subs in parallel on each output. Otherwise you could run all four in a parallel-series combo with the amp bridged. Let me know if you need explanation of "parallel" or "parallel-series" connections.

Did you check your polarities (phasing) carefully? Could be part of the cause of your "mushy" bass. Also, are you doing a mono-mix ahead of the amp? - it might help, just to make sure all subs are getting the exact same signal in exact same phase.

PRAM160:

2 Channels

Power Output (DC14.4V)

RMS At 2 Ohm, Stereo 300Wx 2Ch.

RMS At 4 Ohm, Stereo 200Wx 2Ch.

RMS At 2 Ohm, Bridged 800W

Features:

12dB/Oct. Crossover

Variable High Pass Crossover (30Hz-500Hz)

Variable Low Pass Crossover (30Hz-500Hz)

5 Way Protections

Power And Protection LED

2 Ohm Stable Circuits

Soft Start / Mute Circuit

Trimode Output Configurations

Good Luck

Jep

 

[anger 10+ year member]

Yo, Thanks for the specs! It is a mono mix and the polarities are correct...I checked twice before soldering. Is it possible that if I wired the subs for a 4 ohm load, and the amp is rated for a 2 ohm load bridged, that this is why I'm getting bad sound? I'm guessing not, but below is how I did it for reference:

How would you suggest I wire them. Again, thanks for your help.

 

[Jepalan]

Try running each channel separately (not bridged) with two subs in parallel on each channel. This way each channel sees a 2-ohm load. Each channel would be connected like this...

 

[anger 10+ year member]

I see, but won't I get more power from the amp if it's bridged (according to the specs)? If this is the way to go, I'll do it this weekend...I'll need to buy another set of terminals for the box, but I'll do whatever makes it sound right again.

 

[Jepalan]

I see, but won't I get more power from the amp if it's bridged (according to the specs)? If this is the way to go, I'll do it this weekend...I'll need to buy another set of terminals for the box, but I'll do whatever makes it sound right again.

You already said it sounds crappy in the bridged config - so, I do think it is worth trying as I've suggested above. It is not always about the watts - let your ears decide.

In theory, the amp would only be putting around 600 watts into your bridged config at 4-ohms and in the 2-channel config I show above it will put 300 watts per channel (600 watts total) so the 2-channel config is worth a try (in my opinion). By the way - I am highly suspicious of the '800W @2-ohms bridged' spec for this amp.

 

[anger 10+ year member]

Makes sense...I'll give it a shot, with both channels at 2 ohms, this weekend and post the results. Thanks for your time and efforts...much appreciated!

 

[anger 10+ year member]

all good, Thanks Jepalan!

 

[pickup1 5,000+ posts]

you need a better quality amp.

 

[anger 10+ year member]

ya...i'm workin' on that. This'll do for now. Thanks

 

[anger 10+ year member]

Ok...so one last question. I've upgraded my amp. I got a Memphis SRX 1.500. I understand it's not the best, but definitely an upgrade from that ProAcoustic. Sounds 100% better right off the bat.

Now I'm trying to tune it to sound the best it can be. I've use this process in the past ( How to make the bass in your car sound its best ), but am a little skeptical.

Is this really the proper way to set my gains? Again, any advice is appreciated.

I'm reading of people using a MultiMeter to adjust the gain properly...just not sure what I should measure and what that result means I should do...??